What is "foundation muslin"

Foundation \Foun*da"tion\, n. [F. fondation, L. fundatio. See Found to establish.]

1. The act of founding, fixing, establishing, or beginning to erect.

2. That upon which anything is founded; that on which anything stands, and by which it is supported; the lowest and supporting layer of a superstructure; groundwork; basis.

   Behold, I lay in Zion, for a foundation, a stone . . . a precious corner stone, a sure foundation.
   --Is. xxviii. 16.

   The foundation of a free common wealth.
   --Motley.

3. (Arch.) The lowest and supporting part or member of a wall, including the base course (see Base course (a), under Base, n.) and footing courses; in a frame house, the whole substructure of masonry.

4. A donation or legacy appropriated to support a charitable institution, and constituting a permanent fund; endowment.

   He was entered on the foundation of Westminster.
   --Macaulay.

5. That which is founded, or established by endowment; an endowed institution or charity; as, the Ford Foundation.

   Against the canon laws of our foundation.
   --Milton.

   Foundation course. See Base course, under Base, n.

   Foundation muslin, an open-worked gummed fabric used for stiffening dresses, bonnets, etc.

   Foundation school, in England, an endowed school.

   To be on a foundation, to be entitled to a support from the proceeds of an endowment, as a scholar or a fellow of a college.